16.1. Alcohols
A subsection of Chemistry, 9701, through 16. Hydroxy compounds
Listing 10 of 190 questions
S is a secondary alcohol with molecular formula C4H10O. Draw the displayed formula of S.  S is converted to V in a three‑step reaction sequence. S C4H10O step 1 PBr3 T C4H9Br step 2 U C4H9CN step 3 dilute acid V In step1, the secondary alcoholS reacts with PBr3 to produce T, which has molecular formula C4H9Br. Give the systematic name of T. Name the type of reaction that occurs in step1. State the reagentand conditions for step2. Step3 involves heating C4H9CN with dilute acid to form V. Complete the equation for this reaction. C4H9CN + H+ + H2O →  An unlabelled sample contains either S, T or U. The sample produces the infrared spectrum shown. transmittance / % wavenumber / cm–1 Explain how this spectrum confirms that the unknown sample contains U. In your answer identify one relevant absorption in the infrared spectrum and the bond that corresponds to this absorption in the region above 1500 cm–1. 
9701_s21_qp_22
THEORY
2021
Paper 2, Variant 2
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Cyclohexanol and phenol are both solids with low melting points that are fairly soluble in water. OH cyclohexanol phenol OH Explain why these compounds are more soluble in water than their parent hydrocarbons cyclohexane and benzene. Explain why phenol is more acidic than cyclohexanol. For each of the following reagents, draw the structural formula of the product obtained for each of the two compounds. If no reaction occurs write no reaction in the box. reagent product with cyclohexanol product with phenol NaNaOHBr2I2+ OH–an excess of acidified Cr2O2 – Choose one of the above five reagents that could be used to distinguish between cyclohexanol and phenol. Describe the observations you would make with each compound. reagent observation with cyclohexanol observation with phenol
9701_w09_qp_41
THEORY
2009
Paper 4, Variant 1
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Explain why ethylamine is basic. Write an equation showing ethylamine acting as a base, a nucleophile. Why is phenylamine less basic than ethylamine? Alkaloids are naturally-occurring compounds that act as bases. Suggest the structure of the product, E, of the reaction between the alkaloid nicotine and an excess of HCl . E excess HCl nicotine N N CH3 Phenylamine, and substituted phenylamines, are used to make cloth dyes and food colourants. The fi rst step in this process is the production of a diazonium salt. NH2 N N + State the reagents and conditions necessary for this reaction. The diazonium salt is then reacted with a phenol or an aryl amine in alkaline solution. N N N OH N + OH + NaOHNR2 + NaOHN N NR2 Suggest the starting materials needed to synthesise the following dyes. Draw their structures in the boxes provided. N N OH O2N CO2H alizarin yellow R N N N(CH3)2 methyl orange NaO3S Suggest what effect the NaO3S – group in methyl orange has on its properties. This group has no effect on the colour of the compound.
9701_w12_qp_43
THEORY
2012
Paper 4, Variant 3
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Questions Discovered
190